Re: [Qemu-devel] [RFC PATCH 4/5] build-system: add clean-coverage target

[Alex Bennée]

Philippe Mathieu-Daudé <address@hidden> writes:

> Hi Alex,
>
> On 06/20/2018 10:20 AM, Alex Bennée wrote:
>> This can be used to remove any stale coverage data before any
>> particular test run. This is useful for analysing individual tests.
>>
>> Signed-off-by: Alex Bennée <address@hidden>
>> ---
>>  Makefile               | 11 +++++++++++
>>  docs/devel/testing.rst | 11 ++++++++---
>>  2 files changed, 19 insertions(+), 3 deletions(-)
>>
>> diff --git a/Makefile b/Makefile
>> index e46f2b625a..cb4af8bf80 100644
>> --- a/Makefile
>> +++ b/Makefile
>> @@ -725,6 +725,14 @@ module_block.h: 
>> $(SRC_PATH)/scripts/modules/module_block.py config-host.mak
>>      $(addprefix $(SRC_PATH)/,$(patsubst %.mo,%.c,$(block-obj-m))), \
>>      "GEN","$@")
>>
>> +ifdef CONFIG_GCOV
>> +.PHONY: clean-coverage
>> +clean-coverage:
>> +    $(call quiet-command, \
>> +            find . \( -name '*.gcda' -o -name '*.gcov' \) -type f -exec rm 
>> {} +, \
>> +            "CLEAN", "coverage files")
>
> I also see ".gcno" files.
> From GCC man page:
>
>       -ftest-coverage
>            Produce a notes file that the gcov code-coverage
>            utility can use to show program coverage.  Each
>            source file's note file is called auxname.gcno.

I explicitly left that out - the gcno file is regenerated by the build.
There is no reason to wipe it between coverage runs. A full clean should
remove them however.

>
> Tested-by: Philippe Mathieu-Daudé <address@hidden>
> Adding gcno:
> Reviewed-by: Philippe Mathieu-Daudé <address@hidden>
>
>> +endif
>> +
>>  clean:
>>  # avoid old build problems by removing potentially incorrect old files
>>      rm -f config.mak op-i386.h opc-i386.h gen-op-i386.h op-arm.h opc-arm.h 
>> gen-op-arm.h
>> @@ -1075,6 +1083,9 @@ endif
>>              echo '')
>>      @echo  'Cleaning targets:'
>>      @echo  '  clean           - Remove most generated files but keep the 
>> config'
>> +ifdef CONFIG_GCOV
>> +    @echo  '  clean-coverage  - Remove coverage files'
>> +endif
>>      @echo  '  distclean       - Remove all generated files'
>>      @echo  '  dist            - Build a distributable tarball'
>>      @echo  ''
>> diff --git a/docs/devel/testing.rst b/docs/devel/testing.rst
>> index 66ef219f69..a3652aea14 100644
>> --- a/docs/devel/testing.rst
>> +++ b/docs/devel/testing.rst
>> @@ -161,9 +161,14 @@ GCC gcov support
>>  ``gcov`` is a GCC tool to analyze the testing coverage by
>>  instrumenting the tested code. To use it, configure QEMU with
>>  ``--enable-gcov`` option and build. Then run ``make check`` as usual.
>> -Reports can be obtained by running ``gcov`` command on the output
>> -files under ``$build_dir/tests/``, please read the ``gcov``
>> -documentation for more information.
>> +
>> +If you want to gather coverage information on a single test the ``make
>> +clean-coverage`` target can be used to any existing coverage
>> +information before running a single test.
>> +
>> +Reports can be obtained by running ``gcov`` command
>> +on the output files under ``$build_dir/tests/``, please read the
>> +``gcov`` documentation for more information.
>>
>>  QEMU iotests
>>  ============
>>


--
Alex Bennée